#include <iostream>
#include <cstdio>
using namespace std;

int main()
{
  //因为Linux下一切皆文件，所以，向显示器打印，本质就是向显示器写入，如何理解？
  //C
  printf("hello printf->stdout\n");
  fprintf(stdout,"hello fprintf->stdout\n");
  fprintf(stderr,"hello fprintf->stderr\n");

  //C++
  cout<<"hello cout -> cout" << endl;
  cerr<<"hello cerr -> cerr" << endl;
  return 0;
}
